#region Copyright (c) 2007 Ryan Williams <drcforbin@gmail.com>
/// <copyright>
/// Copyright (c) 2007 Ryan Williams <drcforbin@gmail.com>
/// 
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
/// 
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.
/// </copyright>
#endregion

using System;
using System.Collections.Generic;
using System.Text;

namespace Obfuscar
{
	class Variables
	{
		readonly Dictionary<string, string> vars = new Dictionary<string, string>();
		readonly System.Text.RegularExpressions.Regex re =
			new System.Text.RegularExpressions.Regex(@"\$\(([^)]+)\)");

		public void Add(string name, string value)
		{
			vars[name] = value;
		}

		public void Remove(string name)
		{
			vars.Remove(name);
		}

		public string GetValue(string name, string def)
		{
			string value;
			return this.Replace(vars.TryGetValue(name, out value) ? value : def);
		}

		public string Replace(string str)
		{
			if (string.IsNullOrEmpty(str))
			{
				return str;
			}

			System.Text.StringBuilder formatted = new System.Text.StringBuilder();

			int lastMatch = 0;

			string variable;
			string replacement;
			foreach (System.Text.RegularExpressions.Match m in re.Matches(str))
			{

				formatted.Append(str.Substring(lastMatch, m.Index - lastMatch));

				variable = m.Groups[1].Value;
				if (vars.TryGetValue(variable, out replacement))
					formatted.Append(this.Replace(replacement));
				else
					throw new ApplicationException("Unable to replace variable:  " + variable);

				lastMatch = m.Index + m.Length;
			}

			formatted.Append(str.Substring(lastMatch));

			return formatted.ToString();
		}
	}
}
